Duracell Coppertop Alkaline 9-Volt Batteries (4-Pack) in the 9-Volt Batteries department at Lowes.com
9v Volt Pp3 Battery Holder Connector Storage Case Box Dc Case W/ Wire Lead On/off Switch Cover Durable Switch Accessories - Switch Accessories - AliExpress
PP3 9V Alkaline Battery - Single | Lighthouse-Torches.com
Defibtech Lifeline™ or Lifeline AUTO AED Lithium 9V Battery - (for self checks) - AED Superstore - DAC-410
Duracell Industrial 9V PP3 Professional Alkaline Battery Electrical World